Technical Abstract:
Decapitation of broilers immediately following electrical stunning results in a rapid onset of death and eliminates the possibility of cadavers. These experiments compared the number of bacteria E. coli, coliforms,and total aerobic recovered from the respiratory tract of decapitated and conventional unilaterial neck cut broiler carcasses following immersion scalding in a commercial plant. Heads were removed from stunned and bleeding carcasses as they exited the automated knife, by continuation of the bleed-cut. On each of three replicate sample days, 8 unilaterally bled and 8 decapitated carcasses were collected from the shackle line at the end of bleed-out and following triple-tank immersion scalding. The trachea on each carcass was occluded with a cable tie around the neck, carcasses were individually bagged and transported to the lab. The trachea of each carcass was aseptically cannulated near the thoracic inlet and 60 mL PBS was introduced into the respiratory tract. Each carcass was inverted 30 times and respiratory tract rinses collected. As anticipated, scalding resulted in significantly higher number (by 1 to 2 Log (10) CFU) of E. coli, coliforms, and total aerobic bacteria in respiratory tract rinses. However, the number of bacteria recovered from the respiratory tract rinse of decapitated carcasses was not different than that recovered from bled carcasses at either the pre or post-scald sample sites. These results confirmed that bacteria numbers increase within the respiratory tract during immersion scalding. However, decapitation at the beginning of bleed-out does not influence the number of bacteria recovered following bleeding or following immersion scalding compared to unilaterally bled carcasses.